全文获取类型
收费全文 | 75篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 2篇 |
地球物理 | 20篇 |
地质学 | 29篇 |
海洋学 | 4篇 |
天文学 | 12篇 |
综合类 | 1篇 |
自然地理 | 8篇 |
出版年
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 3篇 |
2009年 | 9篇 |
2008年 | 4篇 |
2007年 | 8篇 |
2006年 | 1篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 218 毫秒
71.
Galina V. Sdasuk 《Geoforum》1976,7(3):193-201
Acceleration of socio-economic progress and the achievement of self-reliant economy by the developing countries are closely linked with transformation of sectoral and spatial structure of colonial type economy, which is characterized by nonintegration, extreme inequalities in resources and land utilization, and regional disparities in the levels of socio-economic development. The State plays the leading role in this process through elaboration and realization of long-term regional policy and regional planning, the necessity of which is admitted in the majority of the developing countries. Their scientific substantiation is connected with investigation of objective process of formation of the spatial structure of the new type economy. The latter is formed in the process of interaction of the major regionalization systems: natural-resources, demography-ethnic, socio-economic (systems of special sector-wise and integral-complex regions are embedded in these systems). The systems of socio-economic regionalization are the most dynamic and manageable. But the modern stage of the development of the Third World countries is characterized by the essential changes of other regionalization systems as well. Evaluation of disproportional correlations in their interaction and elaboration of measures to reduce them constistute one of the most important objects of modern geography. Specialization of economic regions in the productions, which have favourable regional combinations of resources results in acceleration of economic growth because of the benefits of spatial division of labour. At the same time regional specialization and increase of inter-regional linkages strengthens the integration on all-national scale, which is of vital importance for the developing countries. The acute, not only economic but also socio-political problem of rapid backward areas advancement can and must be solved not separately (although such attempts have been undertaken often enough) but as a part of the general strategy of regional development. Scientific substantiation of the effective regional planning in the developing countries is an object of interdisciplinary research, where geographers are called to play the leading role. 相似文献
72.
Christopher I. Chalokwu Norman K. Grant Alexei A. Ariskin Galina S. Barmina 《Contributions to Mineralogy and Petrology》1993,114(4):539-549
In order to describe the composition and crystallinity of the initial (parental) magma of the Partridge River intrusion of the Keweenawan Duluth Complex, and thereby understand the mode of emplacement and solidification of the intrusion, we have applied a numerical simulation technique called geochemical thermometry (Frenkel et al. 1988). The parental magma was a low-alumina, high-Ti-P olivine tholeiite similar to typical Keweenawan low-alumina, high-Ti-P basalts associated with the Duluth Complex and from the nearby Portage Lake area of the Lake Superior region. The parental magma was emplaced as a crystal-liquid suspension, followed by chilling of an evolved, leading edge ferrodioritic liquid in the basal zone of the intrusion. The conditions of emplacement at the present crustal location were 1,150°C, 2 kbar, and f
O
2 slightly above the wustite-magnetite (WM) buffer. The main differentiation process after emplacement was the sorting and redistribution of plagioclase and olivine crystals on a local scale accompanied by less efficient convection and minor settling of olivine. Calculated crystallization sequence for the parental magma is olivine+plagioclase (1,240°C)olivine+plagioclase+magnetite (1,146°C, WM+0.5)olivine+plagioclase+magnetite+augite (1,140°C, WM+0.5). The calculated compositions of the cumulus olivine and plagioclase in equilibrium with the parent magma at 1,150°C are Fo66.7±1.1 and An64.5±2.5, respectively, and are similar to the estimated average composition of primary olivine (Fo69.1±2.8) and the average composition of plagioclase core (An66.3±2.8) measured in drill core samples through the intrusion (Chalokwu and Grant 1987). 相似文献
73.
74.
Satoru Kojima Kazuhiro Tsukada Shigeru Otoh Satoshi Yamakita Masayuki Ehiro Cheikhna Dia Galina Leontievna Kirillova Vladimir Akimovich Dymovich Lyudmila Petrovna Eichwald 《Island Arc》2008,17(4):502-516
The Anyui Metamorphic Complex (AMC) of Cretaceous age is composed of metachert, schist, gneiss, migmatite and ultramafic rocks, and forms a dome structure within the northernmost part of the Jurassic accretionary complex of the Samarka terrane. The two adjacent geological units are bounded by a fault, but the gradual changes of grain size and crystallinity index of quartz in chert and metachert of the Samarka terrane and the AMC, together with the gradual lithological change, indicate that at least parts of the AMC are metamorphic equivalents of the Samarka rocks. Radiolarian fossils from siliceous mudstone of the Samarka terrane indicates Tithonian age (uppermost Jurassic), and hence, form a slightly later accretion. This signifies that the accretionary complex in the study area is one of the youngest tectonostratigraphic units of the Samarka terrane. The relationship between the Samarka terrane and AMC, as well as their ages and lithologies, are similar to those of the Tamba–Mino–Ashio terrane and Ryoke Metamorphic Complex in southwest Japan. In both areas the lower (younger) part of the Jurassic accretionary complexes were intruded and metamorphosed by Late Cretaceous granitic magma. Crustal development of the Pacific‐type orogen has been achieved by the cycle of: (i) accretion of oceanic materials and turbidites derived from the continent; and (ii) granitic intrusion by the next subduction and accretion events, accompanied by formation of high T/P metamorphic complexes. 相似文献
75.
Mikhail Albertovich Phedorin Andrey P. Fedotov Svetlana S. Vorobieva Galina A. Ziborova 《Journal of Paleolimnology》2008,40(1):445-452
The analysis of sediment chemistry and biota in drill cores from Lake Khubsugul in Mongolia (KDP-01) and Lake Baikal in Siberia
(BDP-96/1), two great Eurasian freshwater lakes, detected prominent climate and biological events at 460–420 and 670 kyrs
BP in addition to the orbital cycles of precession, tilt and eccentricity. The revealed long-term events were associated with
notable changes in biodiversity and geography/landscapes, mainly in water budgets and weathering patterns. The span between
460–420 and 670 kyrs BP was the time when the climate and geographic conditions differed from those before and after these
events. The corresponding 33–24 m (670–460 kyr) interval of the Khubsugul core lacked the usual signature of the Milankovitch
glacial/interglacial cycles. Events of approximately these ages were found in some other continental ecosystems and in oceanic
δ13C records. The two events may mark the phases of a 300–500-kyr long supercycle (or megastadial) in the evolution of continental
ecosystems. Among other causes (e.g., regional tectonic events), this periodicity, being globally correlated, may be associated
with the 400-kyr cycle of the Earth’s orbital eccentricity. 相似文献
76.
77.
Galina Churkina Kristina Trusilova Mona Vetter Frank Dentener 《Carbon balance and management》2007,2(1):5-7
Background
The amount of reactive nitrogen deposited on land has doubled globally and become at least five-times higher in Europe, Eastern United States, and South East Asia since 1860 mostly because of increases in fertilizer production and fossil fuel burning. Because vegetation growth in the Northern Hemisphere is typically nitrogen-limited, increased nitrogen deposition could have an attenuating effect on rising atmospheric CO2 by stimulating the vegetation productivity and accumulation of carbon in biomass. 相似文献78.
Galina P. Bulanova Michael J. Walter Chris B. Smith Simon C. Kohn Lora S. Armstrong Jon Blundy Luiz Gobbo 《Contributions to Mineralogy and Petrology》2010,160(4):489-510
We report on a suite of diamonds from the Cretaceous Collier 4 kimberlite pipe, Juina, Brazil, that are predominantly nitrogen-free
type II crystals showing complex internal growth structures. Syngenetic mineral inclusions comprise calcium- and titanium-rich
phases with perovskite stoichiometry, Ca-rich majoritic-garnet, clinopyroxene, olivine, TAPP phase, minerals with stoichiometries
of CAS and K-hollandite phases, SiO2, FeO, native iron, low-Ni sulfides, and Ca–Mg-carbonate. We divide the diamonds into three groups on the basis of the carbon
isotope compositions (δ13C) of diamond core zones. Group 1 diamonds have heavy, mantle-like δ13C (−5 to −10‰) with mineral inclusions indicating a transition zone origin from mafic protoliths. Group 2 diamonds have intermediate
δ13C (−12 to −15‰), with inclusion compositions indicating crystallization from near-primary and differentiated carbonated melts
derived from oceanic crust in the deep upper mantle or transition zone. A 206Pb/238U age of 101 ± 7 Ma on a CaTiSi-perovskite inclusion (Group 2) is close to the kimberlite emplacement time (93.1 ± 1.5 Ma).
Group 3 diamonds have extremely light δ13C (−25‰), and host inclusions have compositions akin to high-pressure–temperature phases expected to be stable in pelagic
sediments subducted to transition zone depths. Collectively, the Collier 4 diamonds and their inclusions indicate multi-stage,
polybaric growth histories in dynamically changing chemical environments. The young inclusion age, the ubiquitous chemical
and isotopic characteristics indicative of subducted materials, and the regional tectonic history, suggest a model in which
generation of sublithospheric diamonds and their inclusions, and the proto-kimberlite magmas, are related genetically, temporally
and geographically to the interaction of subducted lithosphere and a Cretaceous plume. 相似文献
79.
Galina N. Antonovskaya Natalya K. Kapustian Alexander I. Moshkunov Alexey V. Danilov Konstantin A. Moshkunov 《Journal of Seismology》2017,21(5):1039-1053
We present the novel fusion of seismic safety monitoring data of the hydropower plant in Chirkey (Caucasus Mountains, Russia). This includes new hardware solutions and observation methods, along with technical limitations for three types of applications: (a) seismic monitoring of the Chirkey reservoir area, (b) structure monitoring of the dam, and (c) monitoring of turbine vibrations. Previous observations and data processing for health monitoring do not include complex data analysis, while the new system is more rational and less expensive. The key new feature of the new system is remote monitoring of turbine vibration. A comparison of the data obtained at the test facilities and by hydropower plant inspection with remote sensors enables early detection of hazardous hydrodynamic phenomena. 相似文献
80.
Marja Liisa Räisänen Galina Kashulina Igor Bogatyrev 《Journal of Geochemical Exploration》1997,59(3):175-195
The mobility and retention of heavy metals, arsenic and sulphur in podzols from eight areas located north of the Arctic Circle in Finland, Norway and Russia were determined by analyzing the < 2.0 mm fraction, using an ammonium acetate (pH 4.5) extraction in addition to a concentrated nitric acid digestion for the humus samples, and a hot aqua regia digestion for the mineral soil samples. Total C, H and N concentrations were determined in humus and mineral soil samples with a CHN analyser.Ni, Cu, Co and As were strongly enriched in the humus layer in the contaminated sites (Monchegorsk, Kurka, Zapoljarnij) when compared to their concentrations in the parent tills and in podzols from the background sites. In most study sites the illuvial layer showed a low capacity to retain the metals and As, the exception included a strongly eroded profile at Monchegorsk, where Ni was tightly fixed in the illuvial layer while Cu was mobile. In contrast to metals, airborne S was not accumulated in the humus layer, but was accumulated in the illuvial layer, more markedly at eroded sites than in places where the humus was covered as at Monchegorsk. 相似文献